Is “nuclear waste” an outdated term? That’s what William Tucker, author of Terrestial Energy, argues in a recent Wall Street Journal column titled "There Is No Such Thing As Nuclear Waste." To hear him describe it, the nation's spent nuclear fuel—which will no longer find a permanent resting place at Yucca Mountain—is actually pretty useful stuff. In addition to a lot of basically inert uranium-238, those spent fuel rods also contain radioactive isotopes that can be used for medical and industrial purposes, as well as decent amounts of uranium-235 and plutonium, which can be reprocessed and used again as nuclear fuel. If we can just keep reusing that nuclear fuel, Tucker argues, maybe there’s no need for a Yucca-style waste repository, after all.
Unfortunately, there are two big reasons that reprocessing is unlikely to solve the problem of nuclear waste. The first is that it’s not cost-effective, and won’t be for a long time yet. Reprocessing is an expensive undertaking, and mining new uranium for nuclear fuel is—relatively speaking—quite cheap. Harvard nuclear-policy researcher Matthew Bunn calculates that the price of uranium would have to go higher than $360 per kilogram before reprocessing becomes cost-competitive. The current price of uranium is about $100 per kilogram—far below the level at which reprocessing could compete. What's more, Bunn thinks that this price has been significantly inflated by short-term production bottlenecks and is likely to drop in the future.
Of course, if running reactors on reprocessed fuel helped reduce the overall amount of nuclear waste—and therefore the need to build expensive waste repositories —there might be a case for doing so even if it costs more than running them on newly-mined uranium. But if anything, reprocessing actually increases the demands on nuclear-waste repositories. That’s because the most important consideration when designing a long-term waste repository is not the volume of radioactive waste but the amount of heat it gives off. And according to Alison MacFarlane, George Mason University professor of nuclear policy, spent mixed-oxide fuel—which is what’s left over after running a reactor on reprocessed nuclear waste—is about three times as hot as regular spent fuel rods.
It’s possible that, one day, more advanced reactors—fast breeder reactors, say—will be able to cost-effectively make use of spent nuclear fuel to produce electricity. Unfortunately, that day is a long ways off. Until then, nuclear waste will remain nuclear waste.